Is the Player Being Looked at

Hello, I am new to unity and not very experienced. Currently I’ve been trying to make a horror game and I want to make it so that the enemy does and action (attacks) if you look at it (in your screen view). Please give advice if you know how to do thins in C#.

                                THANKS!!! :)

More propper solution would be to test enemy bounding box center position against view cone. Some vector math library was posted on wiki which does this calculus.